1. Field of the Invention
The present invention generally relates to memory cards, and more specifically, to a memory card installed and used in a personal computer, a potable phone, a digital camera, or the like.
2. Description of the Related Art
At present, a normal size memory card and a small size memory card are in the market as memory cards using a semiconductor flash memory chip. The normal size memory card is installed in the personal computer. The small size memory card is installed in the portable phone, the digital camera, or the like. In addition, a micro memory card having a smaller size than the above-mentioned small size memory card is planed to be sold.
The above-mentioned memory cards usually have the same type of semiconductor flash memory. Hence, it is required to efficiently manufacture different kinds of memory cards.
FIG. 1 is an exploded perspective view of a related art memory card 1. The memory card 1 has a structure where a memory chip module 10 is received between a lower case 2 and an upper case 5. A writing protect knob 3 is provided on the lower case 2 and plural windows 4 are provided in line at a head end side of the lower case 2.
The memory chip module 10 has a structure where a semiconductor flash memory chip 12, a control chip 13, and others are mounted on an upper surface 11a of a printed circuit board 11. Plural pad-shaped terminals 15 are formed along a head end edge of a lower surface 11b of the printed circuit board 11.
The pad-shaped terminals 15 are exposed from the windows 3 of the lower case of the memory card 1.
In the meantime, the small size memory card has a structure where a memory chip module for the small size memory card is received between a lower case and an upper case for the small size memory card. See Japan Pre-Grant Patent Publication No. 6-62026.
Thus, if an exclusive memory chip module is installed for every kind of the memory card, memory chip modules having different sizes should be prepared for every kind of the memory cards so that management of parts becomes complicated and it is difficult to reduce the manufacturing cost.
In addition, the above-mentioned pad-shaped terminals 15 includes a gold (Au) plating layer formed by gold-plating on a printed circuit board such as FR4 or the like. Therefore, it is difficult to heighten the mechanical strength and a problem of degraded reliability of an electrical connection in a case where the memory card is installed in an electronic apparatus may happen.